1. Field of the Invention
The present invention relates generally to loudspeakers, and more particularly is directed to an improved diaphragm for a loudspeaker.
2. Description of the Prior Art
It is well known, in the art of loudspeaker design, to provide a diaphragm which is vibrated by a magnetic means having varying electrical signals supplied thereto. The design of a diaphragm for a loudspeaker must take into account numerous considerations among which are the configuration of the loudspeaker and the desired vibratory characteristics of the diaphragm. A failure to take into account any one of these essential considerations could lead to a loudspeaker having deleterious acoustic characteristics.
An important consideration that must be taken into account in designing a diaphragm for a loudspeaker is reducing the weight or mass thereof while ensuring that the diaphragm can structurally withstand the vibratory motion imparted thereto. In furtherance of the foregoing, one prior art diaphragm for a loudspeaker is in the form of a lamination which includes a core member sandwiched between a pair of sheets. The core member is typically of a styrene foam material or of an aluminum material in the form of a honeycomb structure. However, because peripheral edge portions of the core member extending between the sheet members are not rigidified by the latter, unstable vibrations are produced thereat when the diaphragm is caused to vibrate by the magnetic means. In the case of the aluminum honeycomb core member, these unstable vibrations result in extraneous noise and a consequent degenerative acoustic quality of the loudspeaker. In the case where the core member is of a styrene foam material, the vibrations at the peripheral edge of the core member tend to cause the styrene foam material thereat to crumble or disintegrate.
One prior art attempt to solve these problems has been to employ an adhesive agent for filling gaps or depressions in the peripheral edge of the core member. However, this method, especially when employed in the case of the aluminum honeycomb core member, has proved to be undesirable because the adhesive agent causes a substantial increase in the mass or weight of the diaphragm, resulting in a deterioration of the desirable audio characteristics of the loudspeaker.